Researchers have long wondered why ancient people built the famous Easter Island monuments where they did.

Astronomers and astrologers may agree that the Age of Aquarius starts when the vernal equinox point moves out of constellation Pisces and into Aquarius. But when will that be? There’s no definitive answer.

Astrology and astronomy are different systems. In some systems of astrology, signs of the zodiac remain fixed relative to seasonal markers, such as the equinox and solstice points on the sky’s dome.

Celebrating the New Year on January 1 is a civil event, not an astronomical one. And yet nature cooperates to make January 1 a satisfying time to start anew.

Sure it is, says this physicist, but only if you have an object with infinite mass. Here’s the story of how to build a time machine, with a design that’s deceptively simple.

As far back as 40,000 years ago, cave-dwellers in what’s now Turkey, Spain, France and Germany all used a method of date-keeping based on the stars. Some of their cave paintings aren’t just depictions of wild animals; instead they represent constellations in the night sky.